# How effective are low/no carb diets for losing fat? **URL:** \ **Category:** Factual Questions\ **Created:** [March 23, 2013, 3:48pm UTC](https://boards.straightdope.com/t/how-effective-are-low-no-carb-diets-for-losing-fat/653746 "2013-03-23T15:48:41Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [March 26, 2013, 5:35pm UTC](https://boards.straightdope.com/t/how-effective-are-low-no-carb-diets-for-losing-fat/653746/21 "2013-03-26T17:35:10Z")
They seem to work better than many diets for a little quick weight off, like if you need to lose 10# or even more. They are just as worthless as any “diet’ in keeping the weight off. However, that being said, let us say you really wanted to get back in shape, exercise, eating right and so forth. If so, then a ‘quick start” with 6 months of low carb could really work. DSeid makes some good points. ---
**Author:** ![Michael63129](https://avatars.discourse-cdn.com/v4/letter/m/3da27b/32.png) [@Michael63129](https://boards.straightdope.com/u/Michael63129)\ **Post date:** [March 26, 2013, 5:59pm UTC](https://boards.straightdope.com/t/how-effective-are-low-no-carb-diets-for-losing-fat/653746/22 "2013-03-26T17:59:47Z")
> [@bldysabba](#): > > What about proteins that go into muscle? Do they get counted separately from calories? For e.g, if I eat an egg, does it give me i) Proteins that go into muscle or get excreted, and ii) Calories that go into fat or get excreted, or does it work differently? I thought proteins also had a calorific count. This brings up a related observation; the “standard” 2,000 calorie diet is actually 1,985 calories according to the [RDA guidelines](http://en.wikipedia.org/wiki/Reference_Daily_Intake#Food_labeling_reference_tables)for fat (585 calories), protein (200 calories) and carbs (1,200 calories); the latter includes fiber, which isn’t digested and therefore the actual number of calories in a “2,000 calorie” diet is 1,885 calories, and that doesn’t say anything about protein (which, if removed, would mean 1,685 calories of actual food energy, although as DSeid explained, proteins are used for muscle growth and repair but are also being recycled; you can increase protein stores by eating more and building muscle but that isn’t a preferred way to store energy, your body will convert excess protein to fat). ---
**Author:** ![PBear42](https://avatars.discourse-cdn.com/v4/letter/p/ecccb3/32.png) [@PBear42](https://boards.straightdope.com/u/PBear42)\ **Post date:** [March 27, 2013, 1:30am UTC](https://boards.straightdope.com/t/how-effective-are-low-no-carb-diets-for-losing-fat/653746/23 "2013-03-27T01:30:20Z")
> [@bldysabba](#): > > If it seems to you that there’s something wrong in my understanding, it’d be nice if you could set me right. I did. See Post #9. I see you have since “gotten” it. Good. ---
**Author:** ![Deeg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/deeg/32/2955_2.png) [@Deeg](https://boards.straightdope.com/u/Deeg)\ **Post date:** [March 27, 2013, 6:44pm UTC](https://boards.straightdope.com/t/how-effective-are-low-no-carb-diets-for-losing-fat/653746/24 "2013-03-27T18:44:55Z")
> [@yorick73](#): > > This may technically be correct but seems overy simplistic to me. Caloric input is not the only factor here. You must take into account metabolic rate…which may be decreased during weight loss. I was only discussing the balance between calories in and calories out. Calories out is widely variable, based on attributes like activity, size, and metabolic rate. My understanding is that “starvation mode” is wildly over stated. Say someone needs 2000 calories/day to live “normally”. What could the body do to save calories? Some ideas come to mind, like dropping internal body temperature or reducing muscle. However, this isn’t going to magically drop calorie usage to 1000 calories/day. ---
**Author:** ![Surreal](https://avatars.discourse-cdn.com/v4/letter/s/eada6e/32.png) [@Surreal](https://boards.straightdope.com/u/Surreal)\ **Post date:** [March 27, 2013, 7:10pm UTC](https://boards.straightdope.com/t/how-effective-are-low-no-carb-diets-for-losing-fat/653746/25 "2013-03-27T19:10:12Z")
> [@Deeg](#): > > My understanding is that “starvation mode” is wildly over stated. Agreed. > **[Resting energy expenditure in short-term starvation is increased as a result...](https://pubmed.ncbi.nlm.nih.gov/10837292/)** > > Resting energy expenditure increases in early starvation, accompanied by an increase in plasma norepinephrine. This increase in norepinephrine seems to be due to a decline in serum glucose and may be the initial signal for metabolic changes in early... > [@](#): > > Abstract > BACKGROUND: The effects of food restriction on energy metabolism have been under investigation for more than a century. Data obtained are conflicting and research has failed to provide conclusive results. > > OBJECTIVE: The objective of this study was to test the hypothesis that in lean subjects under normal living conditions, short-term starvation leads to an increase in serum concentrations of catecholamines and thus to an increase in resting energy expenditure. > > DESIGN: Resting energy expenditure, measured by indirect calorimetry, and hormone and substrate concentrations were measured in 11 healthy, lean subjects on days 1, 2, 3, and 4 of an 84-h starvation period. > > RESULTS: \*\*Resting energy expenditure increased significantly from 3.97 +/- 0.9 kJ/min on day 1 to 4.53 +/- 0.9 kJ/min on day 3 (P \< 0.05). \*\*The increase in resting energy expenditure was associated with an increase in the norepinephrine concentration from 1716. +/- 574 pmol/L on day 1 to 3728 +/- 1636 pmol/L on day 4 (P \< 0.05). Serum glucose decreased from 4.9 +/- 0.5 to 3.5 +/- 0.5 mmol/L (P \< 0.05), whereas insulin did not change significantly. > > CONCLUSIONS: Resting energy expenditure increases in early starvation, accompanied by an increase in plasma norepinephrine. This increase in norepinephrine seems to be due to a decline in serum glucose and may be the initial signal for metabolic changes in early starvation. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [March 27, 2013, 8:16pm UTC](https://boards.straightdope.com/t/how-effective-are-low-no-carb-diets-for-losing-fat/653746/26 "2013-03-27T20:16:22Z")
Remember though that we are talking about more than the very short term of 4 days, and that Total Energy Expended (TEE) is the the sum of basal metabolic rate (BMR), digestion and subsequent processing of food [thermic effect of food (TEF)], thermoregulation and activity energy expenditure (AEE). The BMR is usually the largest componant but AEE is the most variable. AEE is partly that which is due to that which gets labelled as exercise, and partly that which gets labelled as “Spontaneous Physical Activity” (SPA) or “Non-exercise activity thermogenesis” (NEAT). See [here](http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2764961/) for details. > [@](#): > > Metabolic adaptation occurs when the body adapts to caloric restriction by decreasing resting metabolic rate (RMR), the amount of energy expended while at rest. This decrease is beyond the expected decrease in RMR due to change in energy stores (body mass) [17, 29]. Metabolic adaptation has been observed in calorie restricted humans in clinical studies for 3-8 months [17, 29]. There has been discussion about whether this adjustment will eventually stabilize during longer periods of caloric restriction, however, a laboratory controlled longitudinal 11-year study of calorie restricted Rhesus monkeys found a metabolic adjustment of 13% lower than accounted by altered body composition [33]. There appears to be considerable variance in how much metabolic adaptation inhibits individual weight loss and this variance is currently a topic of serious investigation by medical researchers. > > An adjustment has also been observed in the rate of energy expended due to the thermic effect of food during both overfeeding and caloric restriction studies[15, 27]. This adjustment exceeds the rate of energy expended during digestion beyond changes accounted for in body composition and was examined through a mathematical model in a recent paper by K. Hall [15]. > > Finally, an interesting phenomena observed in caloric restriction and overfeeding studies is the change in non-exercise activity thermogenesis or NEAT. The impact of NEAT on resistance to change in body mass has been the focus of several overfeeding studies [21, 25, 27, 39]. C.K. Martin et al. also found that physical activity levels decreased over three months of calorie restriction [29]. … There is also some interesting work that suggests those prone to obesity are less likely to compensate for an overfeeding state with increases in NEAT than those not so prone. So while “starvation mode” may indeed be overstated, the body’s metabolic adaptations on the energy out side are very real. [NEAT alone varies](http://online.liebertpub.com/doi/abs/10.1089/obe.2006.2.146) from 15 to 50% of TEE; it can vary by over 1500 KCal between similarly sized individuals. Put simply “what does a body do?” Over time (longer than the stress reaction forst several days) it lowers BMR and to a greater degree it does not move as much when not exercising. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [March 27, 2013, 8:27pm UTC](https://boards.straightdope.com/t/how-effective-are-low-no-carb-diets-for-losing-fat/653746/27 "2013-03-27T20:27:07Z")
And since the suitability of a “low carb” diet for the op’s purposes has been pretty roundly agreed upon, allow me get some reaction here to [an article](http://www.bmj.com/content/344/bmj.e4026) that gives me some pause. I say pause because my bias has been that a nutrition plan relatively high in protein (20 to 30%) is a good idea. ---
**Author:** ![barbitu8](https://avatars.discourse-cdn.com/v4/letter/b/839c29/32.png) [@barbitu8](https://boards.straightdope.com/u/barbitu8)\ **Post date:** [March 27, 2013, 9:02pm UTC](https://boards.straightdope.com/t/how-effective-are-low-no-carb-diets-for-losing-fat/653746/28 "2013-03-27T21:02:57Z")
> [@DSeid](#): > > And since the suitability of a “low carb” diet for the op’s purposes has been pretty roundly agreed upon, allow me get some reaction here to [an article](http://www.bmj.com/content/344/bmj.e4026) that gives me some pause. I say pause because my bias has been that a nutrition plan relatively high in protein (20 to 30%) is a good idea. From your link: > [@](#): > > With respect to the biomedical plausibility of our findings, vegetables, fruits, cereals, and legumes, which have been found in several studies to be core components of healthy dietary patterns,34 35 are important sources of carbohydrates, so that reduced intake of these food groups is likely to have adverse effects on cardiovascular health. Moreover, several studies have reported that meat consumption or high intake of protein from animal sources may increase the risk of cardiovascular disease.31 So the sources of the carbs and proteins are important. ---
**Author:** ![Doubticus](https://avatars.discourse-cdn.com/v4/letter/d/e56c9b/32.png) [@Doubticus](https://boards.straightdope.com/u/Doubticus)\ **Post date:** [March 27, 2013, 9:36pm UTC](https://boards.straightdope.com/t/how-effective-are-low-no-carb-diets-for-losing-fat/653746/29 "2013-03-27T21:36:13Z")
My wife went from 145 lbs to 116 lbs over the course of four months by basically avoiding breads, pasta and fat. From my understanding it is a lot like the Paleo Diet. ---
**Author:** ![Michael63129](https://avatars.discourse-cdn.com/v4/letter/m/3da27b/32.png) [@Michael63129](https://boards.straightdope.com/u/Michael63129)\ **Post date:** [March 28, 2013, 12:20am UTC](https://boards.straightdope.com/t/how-effective-are-low-no-carb-diets-for-losing-fat/653746/30 "2013-03-28T00:20:34Z")
> [@barbitu8](#): > > From your link: So the sources of the carbs and proteins are important. Indeed; that study notes that meat raises the risk of CVD, but a large meta-analysis (1.2 million people across 20 studies) found no such link - [except for processed meat](http://www.webmd.com/heart-disease/news/20100517/processed-meat-linked-to-heart-disease-risks). In fact, the study (posted by **DSeid** ) even says: > [@](#): > > Also, differences in the way protein sources, and perhaps also carbohydrate sources, are **prepared and processed** might explain, to a certain extent, diverging results from studies in different populations. Well, of course; few people would ever say that bacon is part of a healthy diet, or a doughnut. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [March 28, 2013, 4:37pm UTC](https://boards.straightdope.com/t/how-effective-are-low-no-carb-diets-for-losing-fat/653746/31 "2013-03-28T16:37:01Z")
The authors speculate that the source matters (at least animal vs plant, no analysis attempted visavis processed foods) but they found only some “suggesion” that such was true. > [@](#): > > We found a suggestion that the incidence rate ratios tended to be higher among women whose protein intake was mainly of animal rather than plant origin, although the formal tests for interaction were generally non-significant … The associations of low carbohydrate, high protein, and low carbohydrate-high protein scores with cardiovascular outcomes were not, in general, statistically significantly different between women whose protein intake was mainly of animal origin and those whose protein intake was mainly of plant origin. Honestly I was surprised. Yes it is possible that high protein low carb correlated with more processed meats consumption while high carb low protein did not correlate with high amounts of similarly harmful processing, but such seems like a little bit of a stretch to me. ---
**Author:** ![Michael63129](https://avatars.discourse-cdn.com/v4/letter/m/3da27b/32.png) [@Michael63129](https://boards.straightdope.com/u/Michael63129)\ **Post date:** [March 28, 2013, 9:31pm UTC](https://boards.straightdope.com/t/how-effective-are-low-no-carb-diets-for-losing-fat/653746/32 "2013-03-28T21:31:19Z")
> [@DSeid](#): > > The authors speculate that the source matters (at least animal vs plant, no analysis attempted visavis processed foods) but they found only some “suggesion” that such was true.Honestly I was surprised. Yes it is possible that high protein low carb correlated with more processed meats consumption while high carb low protein did not correlate with high amounts of similarly harmful processing, but such seems like a little bit of a stretch to me. Well, it also has to be taken into account that the study involved just 43,000 women, while the meat study I linked to involved multiple studies (20) adding up to 1.2 million men and women. And of course, the one I have previously cited about dairy (an animal protein source) actually _reducing_ CVD risk (also involving a very large number of people over numerous studies, with the number of studies being just as important, since one bad study wouldn’t throw the conclusions off as much). And anyway, what in animal protein, which has the same amino acids, would make it harmful to health? What about groups like the Inuit and others (not just those who ate fish; see the Paleo diet) who enjoyed relatively low rates of CVD until they started eating a Western diet? Another possibility is that even unprocessed meat may contain preservatives according to [this more detailed discussion](http://www.scientificamerican.com/article.cfm?id=meat-of-the-matter-modern-methods-preserving-cooking-meat-healthy&page=3) on the study I mentioned above: > [@](#): > > The biggest discrepancy is the level of salt and other preservatives: processed meats generally contain four times more sodium than red meats and 50 percent more preservatives… Not “contains preservatives”, but “50 percent _more_ preservatives” (so does this mean that a “100% beef/no preservatives” label, and/or nothing other than meat listed in the ingredients, isn’t telling the truth?). ---
**Author:** ![treis](https://avatars.discourse-cdn.com/v4/letter/t/bc79bd/32.png) [@treis](https://boards.straightdope.com/u/treis)\ **Post date:** [March 28, 2013, 11:27pm UTC](https://boards.straightdope.com/t/how-effective-are-low-no-carb-diets-for-losing-fat/653746/33 "2013-03-28T23:27:40Z")
> [@bldysabba](#): > > A handheld impedance body fat measurement device puts me between 19 to 20% body fat. Ignore this reading as impedence body fat measurements basically don’t work. As to low/no carb diets, these work for three relatively obvious reasons: (1) Your body needs a certain amount of protein and fat to operate correctly. Assuming you are relatively close to consuming the correct levels of these nutrients, all that’s left to cut are carbs. (2) Most junk food is high in carbs. Ice cream, cookies, chips, candy, and basically anything most people snack on is high in carbs. If you cut these out you are going to reduce your calorie intake which will lead to weight loss. (3) Lean protein has some of the highest satiation to calorie ratio of food. 400 calories of chicken breast is going to leave people feeling fuller than 400 calories of cookies or cheese. I’m generally dubious of any claims about altering biochemistry. Anything that results in a less efficient use of calories would be heavily selected against from an evolutionary perspective. While I’ll acknowledge the possibility, you need to have some damn good evidence that something is happening. ---
**Author:** ![Septima](https://avatars.discourse-cdn.com/v4/letter/s/dc4da7/32.png) [@Septima](https://boards.straightdope.com/u/Septima)\ **Post date:** [March 28, 2013, 11:44pm UTC](https://boards.straightdope.com/t/how-effective-are-low-no-carb-diets-for-losing-fat/653746/34 "2013-03-28T23:44:36Z")
What made it a miracle cure in my case (and I realize this is personal, and may vary, but also fairly typical) is that the diet in itself acted as an appetite suppressant, so I ate a lot smaller portions and lost all cravings for snacks and junk food. So I wound up eating a lot less and a lot healthier with virtually no effort. ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [March 28, 2013, 11:50pm UTC](https://boards.straightdope.com/t/how-effective-are-low-no-carb-diets-for-losing-fat/653746/35 "2013-03-28T23:50:31Z")
> [@treis](#): > > Ignore this reading as impedence body fat measurements basically don’t work. > > As to low/no carb diets, these work for three relatively obvious reasons: > > (1) Your body needs a certain amount of protein and fat to operate correctly. Assuming you are relatively close to consuming the correct levels of these nutrients, all that’s left to cut are carbs. > > (2) Most junk food is high in carbs. Ice cream, cookies, chips, candy, and basically anything most people snack on is high in carbs. If you ackcut these out you are going to reduce your calorie intake which will lead to weight loss. > > (3) Lean protein has some of the highest satiation to calorie ratio of food. 400 calories of chicken breast is going to leave people feeling fuller than 400 calories of cookies or cheese. > > I’m generally dubious of any claims about altering biochemistry. Anything that results in a less efficient use of calories would be heavily selected against from an evolutionary perspective. While I’ll acknowledge the possibility, you need to have some damn good evidence that something is happening. I agree mostly. I think a large part of why low carb works is thay so many snack foods are carb based. Once you cut them out, what do you have left? Beef jerky? ---
**Author:** ![yorick73](https://avatars.discourse-cdn.com/v4/letter/y/b5a626/32.png) [@yorick73](https://boards.straightdope.com/u/yorick73)\ **Post date:** [March 29, 2013, 12:49am UTC](https://boards.straightdope.com/t/how-effective-are-low-no-carb-diets-for-losing-fat/653746/36 "2013-03-29T00:49:03Z")
> [@Deeg](#): > > I was only discussing the balance between calories in and calories out. Calories out is widely variable, based on attributes like activity, size, and metabolic rate. And, it appears, [gut flora](http://vitals.nbcnews.com/_news/2013/03/27/17488826-after-weight-loss-surgery-new-gut-bacteria-keep-obesity-away?lite) may have a big impact. I haven’t read the study but this shows we really have a lot to learn about how the body extracts energy and utilizes calories. > [@article](#): > > Slimming bacteria work their magic in either of two ways, studies of gut microbiota show. They seem to raise metabolism, allowing people to burn off a 630-calorie chocolate chip muffin more easily. > > They also extract fewer calories from the muffin in the first place. In contrast, fattening bacteria wrest every last calorie from food. Maybe that muffin does have a different effect on you than it does on me. ---
**Author:** ![treis](https://avatars.discourse-cdn.com/v4/letter/t/bc79bd/32.png) [@treis](https://boards.straightdope.com/u/treis)\ **Post date:** [March 29, 2013, 3:03am UTC](https://boards.straightdope.com/t/how-effective-are-low-no-carb-diets-for-losing-fat/653746/37 "2013-03-29T03:03:58Z")
> [@yorick73](#): > > And, it appears, [gut flora](http://vitals.nbcnews.com/_news/2013/03/27/17488826-after-weight-loss-surgery-new-gut-bacteria-keep-obesity-away?lite) may have a big impact. I haven’t read the study but this shows we really have a lot to learn about how the body extracts energy and utilizes calories. > > Maybe that muffin does have a different effect on you than it does on me. I can’t access the full study, but the abstract says: > [@](#): > > revealed that alterations to the gut microbiota after RYGB are conserved among humans, rats, and mice, resulting in a rapid and sustained increase in the relative abundance of Gammaproteobacteria (Escherichia) and Verrucomicrobia (Akkermansia). **These changes were independent of weight change** and caloric restriction If I’m reading that right, the abundance of bacteria was independent of weight change, which seems to be a rather big blow to a cause/effect relationship. As I said before, there are two pretty big arguments against a biologic cause for current obesity rates. (1) If people are obese due to biology, then it means thin people are that way due to biology. Which means for some reason thin people can’t put on fat stores in a time of abundance. This would be selected very, very strongly against by evolution and likely would be weeded out of the population. (2) It doesn’t explain why Obesity rates have risen dramatically over the last 30 years around the world. It’s extremely unlikely that such a significant genetic or biologic change has happened so rapidly across such a broad population. By far the simplest explanation is that food availability and lifestyle cause the majority of cases of obesity. Any other explanation has to bring some really good evidence. ---
**Author:** ![Michael63129](https://avatars.discourse-cdn.com/v4/letter/m/3da27b/32.png) [@Michael63129](https://boards.straightdope.com/u/Michael63129)\ **Post date:** [March 29, 2013, 3:19am UTC](https://boards.straightdope.com/t/how-effective-are-low-no-carb-diets-for-losing-fat/653746/38 "2013-03-29T03:19:52Z")
> [@treis](#): > > (1) If people are obese due to biology, then it means thin people are that way due to biology. Which means for some reason thin people can’t put on fat stores in a time of abundance. This would be selected very, very strongly against by evolution and likely would be weeded out of the population. There are always people who claim to never gain weight regardless of what they eat, but I wonder how much off that is due to them not actually eating as much as they think, or exercising/NEATing it off (and of course there’s the opposite, but again probably due to eating more calories than they need). ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [March 29, 2013, 1:16pm UTC](https://boards.straightdope.com/t/how-effective-are-low-no-carb-diets-for-losing-fat/653746/39 "2013-03-29T13:16:19Z")
For the interested, we’ve [had a brief thread](http://boards.straightdope.com/sdmb/showthread.php?t=662801) on interaction of various gut microbiomes on obesity before, provoked by an observation that use of anitbiotics in infancy is correlated with later obesity risk. The [Economist article](http://www.economist.com/node/21560523) cited and linked to there is the most accessible of the reviews linked to even if it does imply more than the current research completely supports. > [@](#): > > In 2006 Dr Gordon, who works at the Washington University School of Medicine, in St Louis, Missouri, published a study that looked at the mixture of bacteria in the guts of fat and thin Americans. Fat people, he discovered, had more Firmicutes and fewer Bacteroidetes than thin ones. And if dieting made a fat person thin, his bacterial flora changed to match. > > Experiments on mice suggest this is not just a question of the bacteria responding to altered circumstances. They actually assist the process of slimming by suppressing production of a hormone that facilitates the storage of fat, and of an enzyme that stops fat being burned. This may help explain an otherwise weird observation from agriculture, which is that adding antibiotics to cattle feed helps fatten beasts up … > > … Having the wrong sort of bacteria can cause malnutrition, too. … The bugs in the malnourished children lacked both the ability to synthesise vitamins and the ability to digest complex carbohydrates. And when Dr Gordon transplanted some of the microbiomes into specially prepared mice which had, up until that point, had sterile guts, the bacteria induced the same results in the rodents as had appeared in the people they were taken from. Thus it would seem bacteria might cause malnutrition even in someone whose diet would otherwise be sufficient to sustain him. It is a bit of a complex subject being teased out. Without question though gut microbiomes change with obesity to weight loss and different biomes transplanted transfer a predisposition to thinness or fatness. My attempted summary of some of the more detailed literature I cited in that thread was this: > [@](#): > > we co-evolved with diverse microbiomes which could adapt to a wide variety of available nutritional patterns. They have throughout our evolutionary history thrived by helping us thrive, helping us harvest more energy from our food (which typically was much more high fiber than is the modern Western diet) with our bodies in turn co-evolving. The result was a non-linear interplay of satiety signals from SCFAs, signals that helps coordinate effective energy storage, and ones that decrease inflammation. Different genomes have likely different means to deal with these signals. > > Our modern environment is however very different. Our diets trigger inflammation (peripherally and in brain). Our gut diversity is significantly less, both as a consequence of the modern diet, likely from the op posited antibiotic exposures altering microbiomes’ developmental trajectories, and those changes have the potential to amplify upon each other and even more so, intergenerationally. … Meanwhile Tries, looking around you and the paucity of thin people, the relatively few people who are completely resistant to our obesiogenic environment, the conclusion that such resistance was subject to a strong evolutionary pressure to be selected against is quite well suppported. That said it likely is not so simple. You are completely correct however: changes in food availability (and type) and lifestyle … what gets labelled an obesiogenic enviroment … is the major factor. The evidence that that environment effects different people differently based on genetics, epigentics, microbiome, early life and even prenatal experiences, etc. is also indisputable. ---
**Author:** ![yorick73](https://avatars.discourse-cdn.com/v4/letter/y/b5a626/32.png) [@yorick73](https://boards.straightdope.com/u/yorick73)\ **Post date:** [March 29, 2013, 3:45pm UTC](https://boards.straightdope.com/t/how-effective-are-low-no-carb-diets-for-losing-fat/653746/40 "2013-03-29T15:45:47Z")
> [@treis](#): > > I can’t access the full study, but the abstract says: > > If I’m reading that right, the abundance of bacteria was independent of weight change, which seems to be a rather big blow to a cause/effect relationship. I don’t think you are reading that right. I can’t access the full article but I think the point they are making is that the change in gut flora occurs before major weight loss (i.e. weight loss is not the cause of the change in gut flora) Also from the abstract: > [@Abstract](#): > > Transfer of the gut microbiota from RYGB-treated mice to nonoperated, germ-free mice resulted in weight loss and decreased fat mass in the recipient animals relative to recipients of microbiota induced by sham surgery, potentially due to altered microbial production of short-chain fatty acids. [Previous page](https://boards.straightdope.com/t/how-effective-are-low-no-carb-diets-for-losing-fat/653746.md?page=1) [Next page](https://boards.straightdope.com/t/how-effective-are-low-no-carb-diets-for-losing-fat/653746.md?page=3)